Plate holder for mechanical printing



(No Model.)

H. H. E. G. KOHL. PLATE HOLDER FOR MECHANICAL PRINTING.

Patented Apr. 22, 1890.

WITNESSES:

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- BY w 0 A ATTORNEYS UNITED STATES PATENT OFFICE.

HERMANN HEINRICH EDUARD GEORG KOIIL, OF LElPSlC-REUDNITZ, GERMANY.

PLATE-HOLDER FOR MECHANICAL PRiNTiNG.

PECIFICATION forming part of Letters Patent No. 426,283, dated April 22, 1890.

Application filed April 13, 1889. Serial No. 307,176. (No model.) Patented in Belgium April 30, 1889, No. 85,807; in France Hay 12, 1889, No. 136,752; in Italy July 30,1889, XXIII, No. 25,332, and in Switzerland August Z, 1889,1T0. 837.

To all whom it may concern: scribed hereinafter, and linally pointed out Be it known that I, HERMANN HEINRICH in the claims.

EDUARD GEORG KOHL, of Leipsic-Reudnitz, In the accompanying drawings, Figures 1 Germany, a citizen of Germany, have inand 8 represent front views of my improved vented certain new and useful Improvements plate-holder before and after shifting the 55 in Photographic-Plate Holders, (for which 1 same. Fig. 2 is a horizontal section of the have received patentsin France May12, 1889, same on line a, Fig. 1.; and Fig. 4 is a detail No.136,752; in Italy, July 30,1889, IXIII, No. horizontal section showing'the clampingmech- 25,332; in Switze'rland, August 2, 1SS9,N0. S37; anism for the line-plate on a larger scale.

in Belgium,April30, 1889,N0. 85,807,) of which Similar letters of reference indicate corre- 6c the following is a specification. spondin g parts.

For the purpose of producing printing- Referring to the drawings, A represents the plates in lines or stipples from photographs transparent or diaphanous plate, which is or other objects in nature it is necessary to provided with a system of parallel lines in the divide the half-tones of the picture by means usual well-known manner. The line-plate A of a net-work of lines into a system of lines is supported in a circular metallic frame B, or dots. For this purpose a transparent or which is guided in a circular shouldered or diaphanous plate provided with a system of grooved opening D of theplate-holderO of the lines is placed in front of the sensitive plate photographic camera and retained therein by 20 into a plate-holder of the photographic eamprojecting lugs or clips E. The line-plate A era and then the sensitized plate exposed, is supported in thecircularframeBbygrooved the plate-holder closed, and in the dark-champarallel strips G and H, of which the strip ll is her a second transparent or diaphanous plate secured to the ring-frame B, while the strip G provided with a system of parallel lines is connected by means of set-screws O with 2 5 placed in such a manner in front of the negaplates 0, that are attached to the frame B, tive that the lines of the second plate cross as shown in Figs. 1, 2-3, and i. A rotary mothe lines of the first plate at an angle of ninety tion through an angle of ninety degrees can degrees. The plate-holder is then again inbe given to the frame 13 of the line-plate by serted into the apparatus and exposed again. means of a cord or gut string K, which is at- 30 As the system of lines of the transparent or tached at the back and guided along the cir- 8o diaphanous plates are first horizontal and cular frame B and thenconducted through a then vertical, or inclined in one direction and lateral hole T to the outside of the plate-holder. then inclined in another direction, or vice '11 and o are fixed stops on the plate-holder, versa, they produce on the negative the corone at the upper part and the other at one 35 responding system of cross-lines, without side of the same. By pulling the cord K the which the negative would not be adapted for lineplate is turned ninety degrees until the producing from the same printing-plates in pin P on the frame B abuts against the stop 0. relief. In the process described the chang- The cord or gut string is retained on the ing of the line-plates is tedious and objecframe B by means of a retaining-spring F,

40 tionable, especially as the position of the negawhich holds the same in contact with the eiro tive may be slightly changed, and thereby cumference of the frame. be doubled by exposures. These objections In using the apparatus it is only necessary are intended to be remedied by the plateto bring the line-plate A in its initial posiholder, which forms the subject-matter of this tion, (shown in Fig. 1,) after which the sensi- 5 application and which consists of a rotary tized plate is partly exposed. The cover is line-plate which is attached to a ring that is then placed on the lens-tube of the camera guided in a grooved circular opening of the and the line-plate turned by the cord K, so plate-holder, the said ring being moved with that it assumes its second position at right the line-plate through an angle of ninety deangles to the former position, as shown in 50 grees by means of a cord, as will be fully de Fig. The cover is then removed and the sensitized plate exposed again until it is completed. In this manner a system of lines is produced on the plate until the half-tones of the plates are dissolved into lines or stipples in the Well-known manner. 4

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A plate-holder for photographic cameras, having a circular guide-opening, combined with a rotary circular frame guided in said opening, a line-plate supported in the rotary frame, and means, substantially as described, for turning the frame of the line-plate at an angle of ninety degrees, substantially as set forth.

2. The combination, with a plate-holder having a circular guide-opening, of a rotary frame guided in the said opening, a line-plate mounted in grooved strips of said rotary frame, set-screws for adjusting said strips, a string for rotating the frame of the line-plate, a pin on said movable frame, and stops for arresting the motion of the movable frame, substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

HERMANN HEINRICH EDUARD GEORG KOIIL. lVitnesses:

CARL BORNGRAEBER, ROBERT UHLAND. 

